This invention relates to a new copolymerization process and to new terpolymers and tetrapolymers having functional groups which can be obtained thereby.
It is well known to copolymerize certain olefinic and vinyl monomers in the presence of free-radical generating initiators. Some olefinic monomers, such as propylene, isobutylene, and butene either cannot be polymerized at all in the presence of free-radial initiators or can be polymerized only to low molecular weight polymers. Polymerization of diolefins or divinyl compounds by a free radical process leads to highly crosslinked polymers which are of limited practical value.
Coordination catalysts, which allow a much better control of the polymerization process, often are not suitable for use with monomers having functional groups containing elements other than carbon and hydroger. Usually, coordination catalysts tend to complex with polar functional groups and such complexed catalysts either become completely deactivated or decay at a fast rate.
Copolymers of olefinic monomers with several monomers containing functional groups have been reported. Terpolymers of ethylene with propylene and certain unsaturated acid amides, nitriles, anhydrides, and esters have also recently been described in U.S. Pat No. 3,278,495. However, neither terpolymers of ethylene and .alpha.-olefins with monomers containing other functional groups nor tetrapolymers of ethylene with .alpha.-olefins, dienes and functional monomers are known.